The present invention relates to data processing by digital computer, and more particularly to a service-oriented architecture for accessing reports in legacy systems.
Large-scale business software applications are sometimes thought of as having a “front-end component” and a “back-end” component. The front-end component can include a graphical user interface (GUI) to present data to users and accept data entry from users. Such front-end components are customized for specific customers. The back-end component stores business data and processes the business data according to business logic. The back-end component retrieves, generates, and maintains the business data. The back-end component is usually responsible for the consistency and correctness of the data. The back-end component also can store relationships between the various data. In a typical business software application, the front-end component includes application code to display and aggregate data of the back-end and provides help to generate requests to the back-end for update operations.
The data managed by the back-end is commonly stored in a relational database. Typically, a relational database presents data in the form of multiple two dimensional tables where each table represents an entity type and each row in each table represents an entity. An attribute is a description of a characteristic of an entity or entity type. Typically, an attribute is specified in a field or a column in a database table. Entity types can also have relationships that enable linking one or more entities of an entity type to other entities of another entity type. This linking can be done using foreign keys by having one or more fields in one table pointing to a primary key of a second table. This enables traversing from a set of entities in one table to related entities in another table.
One example of an architecture supporting integrated business applications that use a front-end component and a back-end component is SAP R/3, available from SAP AG of Walldorf (Baden), Germany. In SAP R/3, the front-end component is included in a presentation layer and the back-end component is included in a database layer. Between the presentation layer and database layer is an application layer. Among other features, SAP R/3 includes the ABAP list viewer (ALV), which is a reporting tool for organizing and displaying data from the back-end component based on search criteria.